Right, as part of my ongoing efforts to build my ultimate Hi-Fi/HT rig I need to get 5 channels of unbalanced pre balanced to feed into my active crossovers. As I have a 300VA 55-0-55 traffo and lots of other suitable bits in my spares box, I obviously thought of breaking my PassLabs virginity and building a BLS.
So, the questions-
1) Would I be better building a psu stage for each pair of amps, as per the normal design, or can I upgrade the existing PSU to provide the required power?
2) Is there any benefit in providing more capacitance on the PSU rails, or is 10000uf more than sufficient.
3) I was looking at the Onsemi website a few days ago, and I noticed they have a new range of mosfets, has anyone used them yet? I'm just wondering if they would sound any better.
4) Anyone got any specific component recommendations for the BLS?
Thanks a lot
Al
So, the questions-
1) Would I be better building a psu stage for each pair of amps, as per the normal design, or can I upgrade the existing PSU to provide the required power?
2) Is there any benefit in providing more capacitance on the PSU rails, or is 10000uf more than sufficient.
3) I was looking at the Onsemi website a few days ago, and I noticed they have a new range of mosfets, has anyone used them yet? I'm just wondering if they would sound any better.
4) Anyone got any specific component recommendations for the BLS?
Thanks a lot
Al
1) 1 psu (in your case regulator; just one toroid right?) per channel is best (the pass transistors gets HOT). Or you can scale it (ZV3.pdf)
2) 10000uF is what I use for C101/102 (really overkill, I know..) and 1000uF for C103-105, else as original , as I recall Nelson recommends to double all C's.
3) try the IRF510 -very nice.
4) 750/1500 ohm: Caddock MP915/930. Good, low impedance C's. Ultrasoft diodes. Elna/DACT I/P selector, DACT attenuators/homebrew with Elma/ 0,1% resistors.
2) 10000uF is what I use for C101/102 (really overkill, I know..) and 1000uF for C103-105, else as original , as I recall Nelson recommends to double all C's.
3) try the IRF510 -very nice.
4) 750/1500 ohm: Caddock MP915/930. Good, low impedance C's. Ultrasoft diodes. Elna/DACT I/P selector, DACT attenuators/homebrew with Elma/ 0,1% resistors.
Thanks for the reply K
So, I need to build a reg stage for each channel, fair enough, it probably keeps the isolation between channels.
But, do I need the bridge and the big caps per channel, or can I have a big reservoir bank and feed the seperate pass regulators on their own boards. I know what the purist answer would be, but I am not well off at the moment, and I need to be in the Frugalphile (tm) frame of mind!
So, I need to build a reg stage for each channel, fair enough, it probably keeps the isolation between channels.
But, do I need the bridge and the big caps per channel, or can I have a big reservoir bank and feed the seperate pass regulators on their own boards. I know what the purist answer would be, but I am not well off at the moment, and I need to be in the Frugalphile (tm) frame of mind!
whoops! sorry for late answer, but I didn't notice your reply until now. I would make one (dual) bridge and a pair of bigguns (or better CRC or CLC). Then you make one reg per channel (without b101/b102). I would recommend to toss in a 10-220uF for c101/b102 though.
I would take: toroid, dual rectifiers (StealthTM from Fairchild), CRC (10000uF*/10 Ohm 5W (wirewound)/10000uF*(=Rifa PEH200, 100V), and 1000uF* for C101-106, but this is overkill.
Having a reg for each channel helps to minimize crosstalk between channels.
I would take: toroid, dual rectifiers (StealthTM from Fairchild), CRC (10000uF*/10 Ohm 5W (wirewound)/10000uF*(=Rifa PEH200, 100V), and 1000uF* for C101-106, but this is overkill.
Having a reg for each channel helps to minimize crosstalk between channels.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.